This game carries much the same sort of humour as the TV show – so if you're not a fan of Adult Swim style humour, then this isn't the game for you. Having said that, for someone who IS a fan, like myself, this game will have you laughing the whole way through – it has a great variety of old and new jokes within it.
The actual gameplay is almost exactly like that of Phoenix Wright – differences being that without a touch screen you just have to scroll through options rather than seek them out yourself, which sadly takes some of the challenge out of it. I would say that there is a similar degree of problem solving in this game though – particularly in trying to seek out new evidence.
The cases, though very funny, I found often lacked a resolved ending – but then, this is a game that was intended entirely for humour rather than gameplay, I believe. The game is also a lot shorter than I thought it would be – having played Phoenix Wright, I'm used to cases taking a few hours to solve. In Harvey Birdman, each case took about half an hour to an hour to solve, which meant that I finished the game in a night.
Overall though, this game is great for a bit of light hearted gameplay, and I would highly recommend it to fans of Adult Swim and Phoenix Wright.